Graphene is a thin planar sheet of carbon atoms that are densely packed in a honeycomb lattice. FIG. 1 schematically illustrates the arrangement of carbon atoms within a graphene layer 1.
The graphene layer 1 illustrated in FIG. 1 comprises only a single layer of carbon atoms. Other graphene layers may comprise a plurality of overlaying layers of carbon atoms. The physical properties of a graphene layer may be dependent upon the number of overlaying layers of carbon atoms. The physical properties of the graphene may become less distinct as the number of atomic layers is increased. The physical properties may be most distinct for graphene comprising up to five atomic layers. If the material comprises more than about twenty atomic layers then the material may no longer be considered to be graphene but graphite instead.
Graphene has been shown to exhibit physical properties such as high charge carrier mobility with ballistic transport, high current density and high thermal conductivity. These properties may enable graphene to be used in microelectronic or nanoelectronic devices.
In order to enable graphene to be used in a microelectronic or nanoelectronic device it is necessary to prepare a suitable portion of graphene and enable a reliable electrical connection to be made to the graphene portion.